Be more careful to check input string lengths as well as values

 when deciding whether a field is a year field.  Assume *anything* longer
 than 2 digits (if it isn't a special-case doy) is a valid year.
 This should fix the "Y1K" and "Y10K" problems
  pointed out by Massimo recently.
Check usage of BC to require a positive-valued year; before just used it
 to flip the sign of the year without checking. This led to problems
 near year zero.
Allow a 5 digit "concatenated date" of 2 digit year plus day of year.
Do 2->4 digit year correction for 6 and 5 digit "concatenated dates".
 Somehow forgot this originally. Guess not many folks use it...

diff --git a/src/backend/utils/adt/dt.c b/src/backend/utils/adt/dt.c
index f08d70ccc533821c3a2954d01cf352df1d0c79f9..24137d5b31ec953a634ed1ba09ba49ee75d290e9 100644 (file)
--- a/src/backend/utils/adt/dt.c
+++ b/src/backend/utils/adt/dt.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/dt.c,v 1.60 1998/12/31 16:30:57 thomas Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/dt.c,v 1.61 1999/01/10 17:20:54 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2839,12 +2839,15 @@ DecodeDateTime(char **field, int *ftype, int nf,
            case DTK_NUMBER:
                flen = strlen(field[i]);
 
-               if (flen > 4)
+               /* long numeric string and either no date or no time read yet?
+                * then interpret as a concatenated date or time... */
+               if ((flen > 4) && !((fmask & DTK_DATE_M) && (fmask & DTK_TIME_M)))
                {
                    if (DecodeNumberField(flen, field[i], fmask, &tmask, tm, fsec) != 0)
                        return -1;
 
                }
+               /* otherwise it is a single date/time field... */
                else
                {
                    if (DecodeNumber(flen, field[i], fmask, &tmask, tm, fsec) != 0)
@@ -3000,7 +3003,12 @@ DecodeDateTime(char **field, int *ftype, int nf,
 
    /* there is no year zero in AD/BC notation; i.e. "1 BC" == year 0 */
    if (bc)
-       tm->tm_year = -(tm->tm_year - 1);
+   {
+       if (tm->tm_year > 0)
+           tm->tm_year = -(tm->tm_year - 1);
+       else
+           elog(ERROR,"Inconsistant use of year %04d and 'BC'", tm->tm_year);
+   }
 
    if ((mer != HR24) && (tm->tm_hour > 12))
        return -1;
@@ -3375,8 +3383,23 @@ DecodeNumber(int flen, char *str, int fmask, int *tmask, struct tm * tm, double
    printf("DecodeNumber- %s is %d fmask=%08x tmask=%08x\n", str, val, fmask, *tmask);
 #endif
 
-   /* enough digits to be unequivocal year? */
-   if (flen == 4)
+   /* Special case day of year? */
+   if ((flen == 3) && (fmask & DTK_M(YEAR))
+       && ((val >= 1) && (val <= 366)))
+   {
+       *tmask = (DTK_M(DOY) | DTK_M(MONTH) | DTK_M(DAY));
+       tm->tm_yday = val;
+       j2date((date2j(tm->tm_year, 1, 1) + tm->tm_yday - 1),
+              &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
+
+   }
+   /* Enough digits to be unequivocal year?
+    * Used to test for 4 digits or more,
+    * but we now test first for a three-digit doy
+    * so anything bigger than two digits had better be
+    * an explicit year. - thomas 1999-01-09
+    */
+   else if (flen > 2)
    {
 #ifdef DATEDEBUG
        printf("DecodeNumber- match %d (%s) as year\n", val, str);
@@ -3399,18 +3422,8 @@ DecodeNumber(int flen, char *str, int fmask, int *tmask, struct tm * tm, double
 
        tm->tm_year = val;
 
-       /* special case day of year? */
-   }
-   else if ((flen == 3) && (fmask & DTK_M(YEAR))
-            && ((val >= 1) && (val <= 366)))
-   {
-       *tmask = (DTK_M(DOY) | DTK_M(MONTH) | DTK_M(DAY));
-       tm->tm_yday = val;
-       j2date((date2j(tm->tm_year, 1, 1) + tm->tm_yday - 1),
-              &tm->tm_year, &tm->tm_mon, &tm->tm_mday);
-
-       /* already have year? then could be month */
    }
+   /* already have year? then could be month */
    else if ((fmask & DTK_M(YEAR)) && (!(fmask & DTK_M(MONTH)))
             && ((val >= 1) && (val <= 12)))
    {
@@ -3460,10 +3473,15 @@ DecodeNumber(int flen, char *str, int fmask, int *tmask, struct tm * tm, double
 #endif
        *tmask = DTK_M(YEAR);
        tm->tm_year = val;
-       if (tm->tm_year < 70)
-           tm->tm_year += 2000;
-       else if (tm->tm_year < 100)
-           tm->tm_year += 1900;
+
+       /* adjust ONLY if exactly two digits... */
+       if (flen == 2)
+       {
+           if (tm->tm_year < 70)
+               tm->tm_year += 2000;
+           else if (tm->tm_year < 100)
+               tm->tm_year += 1900;
+       }
 
    }
    else
@@ -3527,9 +3545,30 @@ DecodeNumberField(int len, char *str, int fmask, int *tmask, struct tm * tm, dou
            tm->tm_mon = atoi(str + 2);
            *(str + 2) = '\0';
            tm->tm_year = atoi(str + 0);
+
+           if (tm->tm_year < 70)
+               tm->tm_year += 2000;
+           else if (tm->tm_year < 100)
+               tm->tm_year += 1900;
        }
 
    }
+   else if ((len == 5) && !(fmask & DTK_DATE_M))
+   {
+#ifdef DATEDEBUG
+       printf("DecodeNumberField- %s is 5 characters fmask=%08x tmask=%08x\n", str, fmask, *tmask);
+#endif
+       *tmask = DTK_DATE_M;
+       tm->tm_mday = atoi(str + 2);
+       *(str + 2) = '\0';
+       tm->tm_mon = 1;
+       tm->tm_year = atoi(str + 0);
+
+       if (tm->tm_year < 70)
+           tm->tm_year += 2000;
+       else if (tm->tm_year < 100)
+           tm->tm_year += 1900;
+   }
    else if (strchr(str, '.') != NULL)
    {
 #ifdef DATEDEBUG